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LTE-Advanced (LTE-A) offloading is concerned about alleviating traffic congestion for the LTE-A network, which includes the core network and the radio access network (RAN). Due to the scarcity of the radio resource, offloading for the LTE-A RAN is more critical, for which an efficient way is to integrate Wi-Fi with LTE-A to form a heterogeneous RAN environment. An LTE-A UE (User Equipment) with the wi-fi interface can therefore access the Internet via an LTE-A base station of Evolved Node B (eNB) or a wi-fi Access Point (AP). In this paper, wireless network selection for UEs with delay-sensitive traffic in the heterogeneous RAN of LTE-A and wi-fi is addressed. Based on the queueing model of M/G/1, a novel network selection and offloading scheme, namely Delay-Sensitive Network Selection and Offloading (DSO), is proposed. The average system time at LTE-A eNBs and wi-fi APs calculated according to M/G/1 is used for network selection as well as offloading operations in DSO. The benefit of DSO in terms of satisfying the delay budget of UEs and load balancing is demonstrated by the simulation study. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare the effects of conventional sintering (CS) and rapid sintering (RS) on the mechanical and optical properties of different generations of dental zirconia ceramics. Five commercial zirconia ceramics were used for the CS and RS processes. The microstructure, phase composition, biaxial strength, 3-point bending strength, and Vickers microhardness of the zirconia after different sintering processes were studied. Weibull analysis was also used to check the structural reliability of the zirconia. The translucency parameter (TP) and the color difference (ΔE) were determined from the L*, a*, and b* values. The surface morphology of each specimen was dense, with no obvious pores or microcracks. The grain size of the RS group was smaller than that of the CS group. Between the two sintering processes, the same characteristic peaks were detected in the X-ray diffraction (XRD) patterns. There was no statistically significant difference (p > 0.05) in the biaxial strength, 3-point bending strength, or Vickers microhardness in terms of the sintering process. After RS, the Weibull modulus of the materials ranged from 9.3 to 19.3. It seems that the RS process affected the TP and ΔE values to some degree and depended on the zirconia generation. The RS process had no impact on the mechanical properties and produced smaller grain sizes than the CS process. The effect of the RS process on the optical properties depended on the type of material used. These findings should assist the production of dental zirconia restorations through the RS process, which saves time and energy. [ABSTRACT FROM AUTHOR]

Long-Term Evolution (LTE) is a 4G wireless broadband technology developed by the Third Generation Partnership Project. Two duplex modes, namely, frequency division duplex and time division duplex (TDD), are defined in LTE for transmission in both downlink and uplink directions simultaneously. Power saving mechanisms for LTE-frequency division duplex were proposed in the authors' previous work. Applicability of the previously proposed mechanisms to LTE-TDD is investigated in this paper, and the idea of 'virtual time' associated with the mapping mechanism from the virtual time domain to the actual time domain for different TDD configurations is proposed. With the help of the mapping mechanism, 3 revised power saving schemes are proposed to support real-time user equipments and nonreal-time user equipments in LTE-TDD. Simulation study demonstrates the effectiveness of the mapping mechanism as well as the benefit of the proposed schemes in power saving efficiency and real-time support in comparing with the standard-based mechanism. [ABSTRACT FROM AUTHOR]

By introduction of relay nodes, LTE-Advanced can provide enhanced coverage and capacity at cell edges and hot-spot areas. The authors have been researching the issue of power saving in mobile communications technology such as WiMax and Long Term Evolution (LTE) for some years. Based on the previous idea of load-based power saving, two strategies each with associated schemes to integrated relay nodes and user equipment in power saving are proposed in the paper. Simulation study shows the benefit of the proposed schemes in terms of better power saving than the standard-based scheme at the cost of moderately increased delay. Extended discussion about the impact of different load distribution among user equipments and the impact of a worse backhaul link on power saving is also presented in the paper. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The popularity of handheld devices, which are usually powered by batteries, has made power saving an important and practical issue in recent years. Techniques of power saving for user devices using mobile communication systems such as WiMAX and LTE (Long-Term Evolution) are parts of the major focuses in the literature. In this paper, two revised schemes of the authors' previously proposed power saving schemes for IEEE 802.16 are proposed to be applied in LTE. The proposed schemes, namely LTE-LBPS-Aggr and LTE-LBPS-Merge, estimate the input load by traffic measurement and the channel capacity by channel quality indicator (CQI) reports, calculate the length of the sleep cycle, and notify related user equipments (UEs) of the next radio-on time for receiving data. The difference between LTE-LBPS-Aggr and LTE-LBPS-Merge lies in the grouping of UEs for sleep scheduling. LTE-LBPS-Aggr treats all UEs in a group, while LTE-LBPS-Merge allows multiple groups of UEs in sleep scheduling. The simulation study shows that in comparison with standard-based mechanisms, the proposed schemes can achieve better power saving efficiency at the cost of moderate increase on delays and the signaling overhead. [ABSTRACT FROM AUTHOR]

Abstract: Previous works in IEEE 802.16e power saving mainly focused on standard Type I or Type II power saving class. The limitation of adopting Type I or Type II is discussed in the paper, and the idea of Load-Based Power Saving (LBPS) is proposed. The base station in LBPS measures the traffic load and estimates the sleep window size for mobile subscriber stations by setting a threshold for data accumulation. A basic version of LBPS, LBPS-Aggr, is presented in the paper, in which all of the traffic in the network is treated as a single aggregate flow in estimation of the sleep window size. Adopting the idea of group splitting or merging in sleep schedule, two enhanced versions namely LBPS-Split and LBPS-Merge are proposed. Simulation results demonstrate that better power saving efficiency can be achieved by proposed LBPS schemes than standard Type I and Type II. [Copyright &y& Elsevier]

IEEE 802.16 (WiMax) technology is designed to support broadband speeds over wireless networks for the coming era of broadband wireless access (BWA). IEEE 802.16 is expected to provide transmission of high-rate and high-volume multimedia data streams for fixed and mobile applications. As an extension of point-to-multipoint (PMP) configuration, the IEEE 802.16 mesh mode provides a quicker and more flexible approach for network deployment. Multimedia networking requires quality-of-service (QoS) support, which demands elaborate mechanisms in addition to the four service types defined in the specification. By examining standard centralized and distributed scheduling/routing schemes in the mesh mode from QoS aspect, a BS-controlled and delay-sensitive scheduling/routing scheme is proposed in the paper. Associate mechanisms including admission control, flow setup and link state monitoring are also proposed. Integration of the proposed mechanisms is presented as a complete QoS framework. Simulation study has demonstrated that the average delay as well as the delay jitters per hop in the proposed scheme is smaller than that of the distributed scheme and much smaller than that of the centralized scheme. Furthermore, proposed mechanisms can also achieve higher throughput than the contrasts and generate much smaller signaling overhead, making the proposed framework a promising scheme for multimedia support in the IEEE 802.16 mesh network. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Cordycepin, a bioactive compound extracted from Cordyceps sinensis, can induce apoptosis in human OEC-M1 oral cancer cells. However, the exact mechanism is still unclear. The present study aimed to investigate the underlying mechanism of cordycepin-induced apoptosis in OEC-M1 cells. Following treatment with cordycepin, apoptosis was examined and quantified using a DNA laddering assay and a cytokeratin 18 fragment enzyme-linked immunosorbent assay, respectively. Expressions of mitogen-activated protein kinases (MAPKs) and apoptosis-related proteins were detected by the western blot analysis. Our results show that a pan-caspase inhibitor, Z-VAD-FMK, could significantly inhibit cordycepin-induced apoptosis in OEC-M1 cells. In addition, treatment with cordycepin not only activated caspase-8, caspase-9, and caspase-3 but also induced Bid and poly ADP-ribose polymerase cleavages. Furthermore, cordycepin also induced the activation of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase, and p38 MAPKs. Among MAPKs, activation of JNK solely contributed to cordycepin-induced apoptosis with the activation of caspase-8, caspase-9, and caspase-3 and cleavage of PARP. Taken together, the present study demonstrated that cordycepin activated JNK and caspase pathways to induce apoptosis in OEC-M1 cells. [ABSTRACT FROM AUTHOR]

Energy-saving for the LTE-A network with relay nodes in TDD mode is addressed in this paper, and integrated sleep scheduling schemes for relay nodes and user devices under a base station are designed. The authors' two previously proposed ideas, namely, Load-Based Power Saving (LBPS) and Virtual Time, are adopted in the design, and two strategies, namely, top-down and bottom-up each with three LBPS schemes are proposed. In the top-down strategy, the load as well as the channel quality on the backhaul link is first considered to determine the sleep pattern for all relay nodes, and then the sleep schedule for UEs under each relay node is determined accordingly. On the contrary, the load and the channel quality on the access links are first considered and then integrated into the sleep schedule on the backhaul link. Two associated mechanisms for the proposed LBPS schemes to operate in the virtual time domain are also proposed in the paper, i.e., calculation of the virtual subframe capacity and the mapping mechanisms from the virtual time to the actual time. The benefit of the proposed schemes in power saving over the standard-based scheme is demonstrated by the simulation study, and the bottom-up scheme of BU-Split outperforms the other schemes under equally distributed input load as well as the hotspot scenario. Discussion on the tradeoff of the processing overhead and the performance for the proposed schemes is presented in the paper. [ABSTRACT FROM AUTHOR]

Abstract Veneering ceramics should be strongly bonded to zirconia core in order to achieve successfully long-term clinical practice. Indeed, to pursue the high zirconia core–veneering ceramic bonding is still a concerned issue. In this regard, this study was to treat zirconia surface using a 3 wt% Si 3 N 4 solution in 4 M NaOH and to investigate the effect of soaking time (5, 10, and 20 days) on the surface properties of zirconia and shear bond strength between zirconia and veneering ceramics. The residual veneering ceramics on zirconia surfaces and failure modes were also examined after fracture. The results showed that the phase composition of zirconia before and after surface modification was not changed. The elemental mapping and depth profiling consistently revealed the soaking-time-dependent Si content on the zirconia surface. The surface roughness of zirconia was significantly (P < 0.05) increased with the increasing soaking time. When zirconia was treated for 10 days, the shear bond strength value of 27.4 MPa was significantly (P < 0.05) higher than the control (18.6 MPa), associated with greater remaining amounts of veneering ceramics on the zirconia surface. The failure mode of the treated zirconia was almost the mixed failure. On the basis of the data, surface modification using Si 3 N 4 in NaOH solution for zirconia core could be a simple and effective method for enhancing the veneering ceramic–zirconia bonding. [ABSTRACT FROM AUTHOR]

Since a portion of patients with nasopharyngeal carcinoma (NPC) do not benefit much from current standard treatments, it is still needed to discover new therapeutic drugs to improve the prognosis of the patients. Considering that Chinese traditional medicine plays a role in inhibiting tumor progression, in this study, we aimed to investigate whether a Chinese herbal formula, Qing Yan Li Ge Tang (QYLGT), has the anticancer activity in NPC cells and explore the underlying mechanism as well. MTT assay, colony formation assay, immunoblotting assay, and DNA laddering assay were performed to assess cell viability, cell colony formation, protein expression, and DNA fragmentation, respectively. Results show that QYLGT was able to inhibit the cell viability and decrease colony formation ability in NPC cells. QYLGT could also increase the formation of intracellular vacuoles and induce the autophagy-related protein expressions, including Atg3, Atg6, and Atg12-Atg5 conjugate in NPC cells. Treatment with an autophagy inhibitor, 3-methyladenine, could significantly recover QYLGT-inhibited cell viability of NPC cells. In addition, QYLGT did not significantly induce apoptosis in NPC cells. We also found that QYLGT had the ability to activate phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of the rapamycin (mTOR) pathway. Treatment with PI3K inhibitors, LY294002 and wortmannin, or mTOR inhibitors, rapamycin and Torin 1, could not only recover QYLGT-inhibited cell viability of NPC cells but also inhibit Atg3 expression. Taken together, our results demonstrated that QYLGT could induce autophagic cell death in NPC cells through the PI3K/Akt/mTOR pathway. [ABSTRACT FROM AUTHOR]